TOCHIGI, Japan — As part of its Earth Dreams Technology initiative, Honda is launching a slew of new technologies designed to drive the company into the future. In this instance, it includes a range of direct-injected engines, some new safety systems and not one but three new Sport Hybrid systems.
The first of the new Sport Hybrid systems is Intelligent Dual-Clutch Drive (i-DCD). It will be used in small cars and features a 1.5-litre four-cylinder engine that operates on the Atkinson cycle, a seven-speed dual-clutch transmission with an integrated electric motor and a 1.0-kilowatt/hour lithium ion battery.
Where this system differs from the norm is the manner in which the engine and electric motor are decoupled — the twin-clutches in the transmission open to isolate the engine from the electric side, which allows the vehicle to be driven up to 70 kilometres an hour using electrons alone. As the load increases, the engine is fired to life, the clutches close and the gasoline side begins to contribute to the acceleration rate.
The i-DCD proved it to be a very effective and efficient powertrain. I easily coaxed it up to its 70-km/h limit before the engine fired to life. When this happened, the transition from electric to gas/electric was smooth and unflustered.
As with other hybrids, when the driver lifts off the gas, the system goes into its regenerative braking mode, which recharges the battery. Again, contrary to the norm, the brake pedal has a completely natural feel.
The bigger plus is that when compared with Honda’s current Integrated Motor Assist hybrid system (as featured in the CR-Z), i-DCD is 30-per-cent more fuel-efficient and it boasts a 15-per-cent improvement in acceleration. It certainly felt peppy during the test drive.
The second Sport Hybrid system will be offered in both regular and plug-in guises. The Sport Hybrid Intelligent Multi-Mode Drive, or i-MMD, features a 196-horsepower 2.0L Atkinson-cycle engine, an electric continuously variable transmission, a clutching system and two electric motors. One of these is used to drive the vehicle and deliver regenerative braking, while the other is the generator that charges the 1.3-kW/h lithium ion battery and starts the engine when it is needed to power the vehicle.
Under normal driving conditions, the i-MMD system has a top electric-only speed of 60 km/h. It also features three different driving modes: electric only (EV Drive); a purely gasoline-powered mode that uses the clutching system to connect the engine directly to the drive wheels (Engine Drive Mode); and the Hybrid Drive mode that sees both power sources work together to deliver crisp acceleration.
The system is smart enough to pick the most suitable mode according to driver input and driving conditions. This system proved to be very nicely integrated and provided rewarding acceleration and a very smooth transition between electric, gasoline and gas/electric modes.
The more interesting proposition is the plug-in version of i-MMD. It uses the same hardware, but it ups the battery size to 6.7 kWh. Plugging it in sees the battery recharged in three hours using a 110-volt outlet and just one hour using 220 volts.
The inclusion of the plug-in side not only increases the electric-only driving speed to 100 km/h, it also brings an electric-only driving range of 30 km. When this is added to the gasoline/electric hybrid system’s range, it boasts a driving distance of 1,000 km on a tank of gas.
Both the normal and plug-in versions of i-MMD will debut in the 2014 Honda Accord Hybrid, which hits the road this summer.
The system of choice proved to be the Sport Hybrid SH-AWD (Super-Handling All-Wheel-Drive). This system uses essentially the same front-drive components as the i-DCD in that it features a seven-speed dual-clutch transmission with an in-built 33-kilowatt electric motor. Where it differs is in the inclusion of a 3.5L V6 direct-injected engine and the two additional 20-kW electric motors that power the rear wheels.
The advantage this setup brings is manifold — the acceleration pace is scintillating without forsaking the desire for overall fuel efficiency.
While Honda did not give a specific output for the Hybrid’s V6, as used in its non-hybrid application, it produces 310 hp (the hybrid will likely be around 260 hp). Combine this with the 98 hp the three electric motors contribute and the motivation at one’s right foot is, as I say, simply scintillating.
Perhaps more important is the torque vectoring that the two rear electric motors allow. In a corner, the outside rear wheel’s motor is driven faster, while the inner wheel’s motor goes into its regen mode, which applies a drag effect. The efficiency of the system is such that the energy captured by the motor applying the drag supplies 90 per cent of the power required to overspeed the outer motor.
The net effect means much less drain on the battery, so at the end of a long string of sweeping corners there is enough juice left in the battery to provide the wicked acceleration the system supplies when all facets are giving their all.
All of this electronic trickery turns the vehicle into the corner with much less understeer and a reduction in steering wheel input. Suffice it to say it worked exceptionally well, as was ably demonstrated in the Accord test mule. This thing really did ride like it was on rails, even when pushed to the limit.
The first application of this system will be in a hybrid version of Acura’s new flagship RLX, arriving later this year. This system will also form the basis of the NSX drivetrain, though the gas engine will be mounted mid-ship with electric motors powering the front wheels.
— Postmedia News